• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.723-730
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• 2011

Soybean oil used to fry French fries, chicken nuggets, and donuts was exposed to high temperature at $180^{\circ}C$ for 72 h. The effects of frying foods on the thermooxidative stability of soybean oil were evaluated by determining the contents of free fatty acids, peroxides, total polar compounds, and conjugated dienoic acids, and by analyzing dielectric constant, refractive index, iodine value, smoke point, and fatty acid composition. The contents of free fatty acids, total polar compounds, conjugated dienoic acids, dielectric constant, and refractive index increased, whereas iodine value, smoke point, and U/S ratio of fatty acids composition decreased with frying time. All samples of frying oils after 72 h presented free fatty acid contents of below 2.0% and total polar compounds of below 25%, which were within the legal limits. However, peroxide values of frying oils were not directly correlated with frying time. The type of fried food affected the thermooxidative stability of the frying oils, with chicken nuggets being more stable in thermooxidation than French fries and donust. Among physiochemical indicators of frying oil quality, a rapid method including dielectric constant and refractive index can be used in quantity food production.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.304-309
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• 2016

This study was assessed stability of ethanolic extract from Cirsium setidens Nakai that will be applied for development of functional foods and ingredients. We evaluated pectolinarin content, total phenol content and antioxidant activity (DPPH radical scavenging activity and FRAP assay) of ethanolic extract from C. setidens Nakai against various temperature (4, 25 and $50^{\circ}C$) and pH (4.0, 7.0 and 10.0). Our results show that the pectolinarin and total phenol contents in ethanolic extract from Cirsium setidens Nakai slightly reduced during the storage periods. Moreover, the DPPH radical scavenging activity at $4^{\circ}C$ was higher than those of other temperature. Pectolinarin content, total phenol content and DPPH radical scavenging activity of ethanolic extract from Cirsium setidens Nakai at acidic (pH 4.0) and neutral (pH 7.0) pH ranges were higher than at alkaline pH ranges. These results indicate that the optimum storage condition of C. setidens Nakai ethanol extract are temperature $4^{\circ}C$ and pH 4.0-7.0 ranges.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.635-640
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• 1997

The oxidative stability of the potato chip prepared with canola oil fortified with antioxidnats was studied to explore the possibility of substituting it for imported frying fats and oils. BHT, BHA, TBHQ and silicone were added to the oil at a level of 0.02% and 10 ppm, respectively. Potato chip samples were prepared in a commercial scale and stored at $25.0{\pm}0.5^{\circ}C$ for 5 months. The oxidative stability of the extracted oils from potato chips during storage was estimated on the basis of some their physico-chemical changes, such as acid values, peroxide values, iodine values, ansidine values, fatty acid composition of the oils. An organoleptic test for the flavor of the samples was also performed. The oxidative stability of the samlpes was estimated on the basis of the changes of the parameter values. The effectiveness of the antioxidants was in the order of canola oil+TBHQ (0.02%)+silicone (10 ppm) > canola oil+TBHQ (0.02%) > canola oil+BHA (0.02%)+silicone (10 ppm) > canola oil+BHT (0.02%)+silicone (10 ppm) > canola oil+BHA (0.02%) > canola oil+BHT (0.02%) > canola oil. The antioxidant effect of canola oil+TBHQ (0.02%)+silicone (10 ppm) was more salient than any other antioxidant used in the potato chip.

• Food Science and Preservation
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• v.15 no.3
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• pp.352-360
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• 2008

The extraction yield and storage stability of Codium fragile pigments extracted in acetone, ethanol or methanol were studied. Methanol was the most effective solvent for pigment extraction, providing an extraction yield of $25.0{\pm}2.10\;mg/g$ (my base). As shown by TLC and HPLC analysis, chlorophyll a(0.40 mg/g) and chlorophyll b(1.94 mg/g) were the major pigment components in dried Codium fragile. The total chlorophyll content of Codium fragile stored a 40C in light or dark conditions for 30 weeks remained at 23.2% and 58.4% respectively. The effect of metal ions ($Cu^{++}$, $Zn^{++}$, $Fe^{++}$ and $Mg^{++}$) on pigment stability was analyzed Among the four metal ions $Cu^{++}$ was the most effective stabilizer of Codium fragile pigments during storage, and $Zn^{++}$ ion was the second most effective. In the presence of 1 mM $Cu^{++}$, the total chlorophyll retained in Codium fragile stored at 40C in light or dark conditions was increased to 47.0% and 88.8% after 30 weeks storage, respectively. The optimum concentrations of $Zn^{++}$ and $Cu^{++}$ for pigment stabilization under dark conditions were 0.5 mM and 0.1 mM, respectively.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.23-28
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• 1987

The effects of phosphatidyl choline (PC), phosphatidyl ethanolamine (PE), phosphatidyl inositol (PI), phosphatidic acid (PA), phosphatidyl glycerol (PG), and cardiolipin (CL) on the flavor stability of purified soybean oil were studied. Purified soybean oil obtained from soybean oil by silicic acid chromatography does not contain measurable iron, tocopherols and phospholipids. Three hundred ppm of PC, PE, PI, PA, PG, or CL was added to the purified soybean oil, with and without 1ppm ferrous iron added. The flavor stability of sample, which was stored at $60^{\circ}C$ for 10 days in dark oven, was determined by a combination of volatile compounds formation and molecular oxygen disappearence in the headspace of air-tightly sealed serum bottle every 48 hrs. Results showed that, in general, phospholipids worked as prooxidant in the pufified soybean oil without ferrous iron added, and worked as antioxidant in the oil, when added 1ppm ferrous iron. The results also suggest that phospholipids work as prooxidant by increasing the solubility of oxygen on the surface of oil, and work as antioxidant in the oil containing 1 ppm ferrous iron by chelating iron. The results showed that PE and PA are better antioxidants than PC and PG. CL and PI showed the lest antioxidant activities in the oil will 1ppm ferrous iron added.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.1
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• pp.50-55
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• 2023

The present study investigated the effects of forage cutting and baler mixing on the chemical compositions, fermentation indices, and aerobic stability of whole crop rice (WCR) haylage. The WCR ("Youngwoo") was harvested at 48.4% dry matter and ensiled into a 300 kg bale silo with forage cutting (whole crop without cutting vs. 5 cm of cutting length). The WCR forages were ensiled without baler mixing process (CON) or with (MIX). The concentrations of dry matter, crude protein, ether extract, crude ash, neutral detergent fiber, and acid detergent fiber of whole crop rice before ensiling were 48.4, 9.70, 2.57, 6.11, 41.2, and 23.5%, respectively. The forage cutting did not affect the chemical compositions, fermentation indices, microbes, and aerobic stability of WCR haylage (p>0.05). The CON haylages tend to be higher in NDF content (p<0.10). The MIX haylages had lower in lactate (p=0.019), and lactate:acetate ratio (p<0.001). The MIX haylages had higher in lactic acid bacteria (LAB) (p=0.010). Therefore, this study concluded that the fermentation quality of WCR haylage improved by baler mixing, but had no effects by forage cutting.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.344-349
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• 2009

The principal objective of this study was to assess the effects of various ratios of sesame oil to shortening on the characteristics and stability of lipids in Yackwa. The sesame oil to shortening ratios assessed herein were 100:0, 75:25, 50:50, and 1:100. The lipid contents of Yackwa prepared with various shortening ratios ranged from 25.20 to 29.12%. The lipids in these Yackwa consisted primarily of the frying oil (soybean oil), and the oil contents were measured between 84-90%. The fatty acid compositions of the lipids in the Yackwa were unrelated to the ratio of shortening. The fatty acid compositions were as follows: linoleic acid 49.1-51.27%, oleic acid 26.05-26.77%, palmitic acid 10.07-11.71%, linolenic acid 5.51-5.72% and stearic acid 4.51-4.68%. These compositions were similar to that of soybean oil, which was the frying oil used to prepare the Yackwa. The acid value, peroxide value, and carbonyl value of the lipids in Yackwa did not differ with the various shortening ratios used during the storage time. Stability of lipids in Yackwa were mainly effected by frying oil. Our results suggest that shortening should prove useful as a substitute for sesame oil in the preparation of Yackwa.

• Journal of The Korean Society of Grassland and Forage Science
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• v.43 no.3
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• pp.148-155
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• 2023

This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.010⁴ cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 10⁵ cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.404-410
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• 2009

We investigated the physicochemical stabilities and biological activities of ethanol- extracted pigment from marine bacteria Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14. The bacterial pigment of strain Ju11-1 was very stable at pH 5.0 below $25^{\circ}C$. The stability of the pigment showed higher stability in the presence of metal ions such as $Cu^{2+}$ and $Mg^{2+}$. The pigment has activity of free-radical scavenging ($IC_{50}$ $95.2{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $82.3{\mu}g$/ml) against DNA damage in human lymphocytes. The bacterial pigment of strain Ju14 was very stable at pH range between 4.0 and 8.0 below $40^{\circ}C$. In the presence of light, the pigment was also very stable, showing more than 90 percent of remaining absorbance during 14 days at $25^{\circ}C$. The stability of the pigment, when metal ions were present, showed higher stability in all examined metal ions except for $Fe^{2+}$, $Al^{3+}$, and $Cu^{2+}$, especially in the presence of $Na^+$. The pigment has activity of freeradical scavenging ($IC_{50}$ $208.6{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $ 96.4{\mu}g$/m) against DNA damage in human lymphocytes. The result indicates that the bacterial pigments from marine bacteria, Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14 showed higher physicochemical stability and significant effects for reduction in oxidative DNA damage. Therefore, the results suggest that these bacterial pigments could be used as a natural colorant having the advantages of antioxidant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.278-286
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• 1987

The results in vestigated produced fluorescence compounds and mycotoxins, studied stability and toxicity of these compounds which were isolated from varicous moistured rice culture extacts inoculated Aspergillus versicolor IFO 30338, 10 kinds of fluorescence compounds were isolated. Sterigmatocystin was produced $38{\mu}g/kg$ in 16%, $329{\mu}g/kg$ in 25% and $380{\mu}g/kg$ in 35% moistured rice 20 days culture respectively. Aflatoxin $B_1$ was produced $3{\mu}g/kg$ in 25% and $12.6{\mu}g/kg$ in 35% moistured rice 20 days culture. In embryo test of isolated fraction 2, 4 and 6 by T.L.C., $LD_{50}$ of fraction 2 was $40{\mu}g/egg$ and fraction 4,6 was $60{\mu}g/egg$, and these compounds were mostly decomposed and fraction 4 and 6 were partly changed into fraction 2 below pH 2 and above pH 10. fraction 2,4 and 6 were all stable when treated 60 min, at $100^{\circ}C$, but were decomposed $60{\sim}65%$ when treated 60 min at $150^{\circ}C$, $95{\sim}100%$ when treated 10 min at $200^{\circ}C$.